It's difficult to tell where 3D is going. It could be argued reasonably that it's in the same league as colour, or HD. The next evolution of how we view visual media.

REVIEW:
But one major factor is missing from 3D as a generational change, by contrast to HD or colour: no one seems to actually want it.

Sony has been a promoter of 3D content more than any other company. In theatres, television, or gaming, Sony has been all about that extra dimension.

Though not the only console able to do 3D on a 3D capable television, the PlayStation 3 has certainly promoted the capacity more than Xbox. And so, Sony has also created new products intended to enhance and improve the 3D experience. One of these is the Sony Personal 3D Viewer - HMZ-T1.

At a glance the 3D viewer looks not unlike a VR headset from the early 90s, or like Nintendos minor misstep, the Virtual Boy. And the reason it looks like that is, of course, because its doing the same thing.

Inside the futuristic headset are two very small (0.7 inch) screens ,which, as they're practically worn as a contact lens, should be equivalent to a decent sized screen quite close, or a giant screen at some distance.

It should be noted that the word portable is nowhere in the description of the system, though somehow it almost seems like it should be, like an expectation, something that goes without saying.

Maybe it's implied in the term personal? But this is not a portable device. There is a cable that runs from the headset to a proprietary plug, and this is plugged into the front of a special box.

The box then has an input and an output at the back, acting as a pass-through for HDMI to the television. This box is also powered from AC. The Personal 3D Viewer itself has no batteries. It is powered from the breakout box, and this is also its video source. So there is no escaping the need for this particular box, making it eminently unportable.

The cable from box to headset is a reasonable 3.5 metres, so that sets an outer limit on the usable distance from the source. 3.5 metres is enough to get to the couch in most loungerooms, but may be a factor for a few.

While it's logical to wish this device didn't ship with a required ball and chain it really is necessary. Being able to charge the device would mean batteries, and therefore a heavier headset. As it is, it's not especially comfortable, quite awkwardly heavy. It's reasonable to assume from the weight that there are batteries here, but there aren't.

Wearing and setting up the device is a minor mission, especially the first time. The Viewer is simply strapped to the head, bulge to the front. Screens then sit in front of the wearer, and built-in headphones to the side.

Underneath the device, and in some extremely awkward positions, there are a series of buttons, not limited to power and a menu button.

On turning on the device with the power button, a start-up sequence begins, which requires skipping through with the menu button. This rigmarole happens every time the unit is turned on.

Underneath there are also two sliders, which move together to shift the position of the two screens, in the hope that they'll merge into one image.

Assuming all has gone according to plan there should now be three whole dimensions beamed at eyes.

Uncharted 3 was chosen as a good sample of 3D content for the PlayStation 3. Not only is it a good game (by contrast to Killzone 3, for example) but it's a solid story that could potentially benefit from the extra immersion.

The experience was mixed. It's not the 3D Viewer that's the issue here, it's the PlayStation 3 itself. A PlayStation 3 is simply not able to generate the huge amount of pixels required to create two different fields of view in 1080p. In order to be able to do so, it drops the resolution down to a more reasonable 720p. However, in order to show 3D images on a television, the two pictures have to be shown in the same screen at the same time. This means the images are actually interlaced through each other, with two half-height-resolution images being drawn, each on an alternating line. This has the effect of essentially halving the horizontal resolution, a massive cut in detail, which is supremely noticeable on games that have fine definition, such as Uncharted 3 or Killzone 3.

While the immersion might work well, the actual game does not look good at all. The compromises are so great that simply removing the gimmick of 3D play is a better option. Unfortunately this coincides with the other problem with playing games with the Sony Personal 3D Viewer it's quite uncomfortable. The weight of the device wants it to pull forward and down, which loses acuity almost immediately. This highlights a major flaw with the entire principle of a device like this.

There is a major difference between having a tiny screen in front and having a large screen a distance away, and that is margin of error. Tiny changes in position, focus, or adjustment result in noticeable blurring or a loss of 3D effect. For gaming this is particularly challenging, as there isn't an available free hand to adjust the recalcitrant device. However, watching a movie is not only is it better, it's truly exceptional. When watching a 3D Blu-ray, the output of the PlayStation 3 isn't reduced in performance to generate two frames. Actually, it is slightly reduced, as the screen is only 720p capable, but that's not noticeable.

Recent release Tintin proved a good tester, as it's full of fine detail and bright colours, with a range of 3D effects. It's also a fun film, which doesn't hurt. The HMZ-T1 is quite simply the best example of 3D it is possible to view. The main reason for this is that it doesn't get something known as crosstalk. As described above, 3D imagery is generated by squishing two images together in some way, then filtering one out per eye.

In the past this meant a red image and a blue image, with equivalent coloured gels in glasses. Modern cinema 3D uses a polarized image with polarized glasses, while home 3D uses LCD glasses to effectively blind the viewer to alternating images.

All of these technologies have significant flaws, not least that the filtering can be inaccurate or incomplete. This results in artifacts, remnants of image that are supposed to be seen by one eye being ghosted to the other eye. This is crosstalk. Where the HMZ-T1 differs from these methods is that there is and can be no crosstalk.

The eyes are being given completely different information from completely different screens. The 3D image is effectively flawless. The trick to a good experience with film on the Personal 3D Viewer is a surprising one.

The viewer really should lie down. In a prone position on a comfortable couch, the fit of the unit is helped, rather than hindered by the effects of gravity. With the lights off, and the viewer comfortably reclining, the experience of the Sony Personal 3D Viewer can truly shine. It becomes an all-encompassing immersion, with perfect 3D and excellent sound quality. Of course, 2D films are almost as good. But for gaming, the above just doesn't work.

As an active participant in games it feels just wrong to lie down, and this still doesn't fix the dodgy quality of the graphics themselves. It's with regret the HMZ-T1 gets as low a score as it does, because the flaws are with 3D itself, or current techniques, rather than with this device. Ultimately, though, the Sony Personal 3D Viewer has one major critical flaw.

3D, whether at home or the theatre, has been greeted with an eloquent shrug by the general public. It doesn't seem that many will be queuing up to purchase the faintly awkward but optimum version of an experience few wanted anyway. For all its potential, and for all it does well, it's an answer to a question no-one asked.